Pencil sharpener



Jan. 2 1930. v P, 5mg," 1,744,812

PENCIL SHARPENER Filed July 2, 1928 INVENTOR. JZ/LW BY TORNEYS.

Patented Jan. 28, 1930 NrrED STATES PAUL SIIPTR-O'IT, or new YORK, N; Y.

PENCIL SHARPENER Application filed July 2, 1928. Serial No. 289,639.

This invention relates to pencil sharpeners and has for its main object toprovide a sharpener which can be removably mounted on an ordinary lead pencil or the like and is adapted to be retained thereon during the entire life of the pencil so that while on the pencil it can be used to sharpen it whenever desired, thereby insuring always a sharp point.

Another object of this invention is to pro- 19 vide a sharpener which will be simple and cheap to manufacture.

Still another object of this invention is to provide the sharpener with means for automatically feeding it on the pencil.

A further object is to provide the sharpener with meansfor shielding the exposed end of the lead of the pencil.

With'these and other objects in view my invention consists in the novel construction,

combination and arrangement of parts as will be hereinafter more fully described and defined in the appended claims.

In the accompanying drawing in which similar reference characters denote correspending parts, Fig. 1 is an elevation of one embodiment of my sharpener shown in position of use on a pencil; Fig. 2 is a cross section on line 2-2 of Fig. 1 looking in the direction of the arrows; Fig. 3 is an evolution of a part of the convolutions of the sharpener shown in Fig. 1 showing one form of the cutting elements thereon; and Figs. 4c and 5 are evolutions similar to Fig. 3 showing modified forms of cutting elements.

Referring now in detail to the drawing, the sharpener 10 comprises a tubular body adapted to fit over a pencil P and having at one end a feeding element and at the other end a sharpening element.-

In the embodiment of my invention shown in Figs. 1 to 3 the body 10 consists of a coil of steel wire'of which the upper part is cylindrical as at 11 and the lower part conical as at 12. One or several of the convolutions of the cylindrical part of coil 11 are internally screw threaded, which thread is adapted to bite into the material of the pencil casing and to cause the sharpener to automatically feed longitudinally on the latter when turned on its axis.

The convolutions of the conical part 12 of the coil are provided with sharpening elements. These convolutions are suitably spacedor spread apart to leave passages for the shavings of the material during the cutv ting or sharpening operation. Thecutting elements consist of sharp tooth like bites 13 projecting from the inner face of the convolutions into the inner region of the cone. These projections are adapted to bite into "6.0 and cut away the wood or whatever material is used for the casing of the pencil when the sharpener is rotated, and to thereby expose the lead L of the pencil, which will pro ect through the lower open end ofthe conical part 12 of the body 10. The shavings will be allowed to drop out through the interstices or passages 12 between the different convolutions. I

The mode of operation is as follows:

The pencil P with the end to be sharpened is inserted into the upper end of the cylindrical portion of the sharpener and the latter is rotated in the direction of the screw thread, causing it to feed onto the pencil and bring the cutting portion 12 into operation. The

teeth 13 of this cutting portion grind the "wood or other material away in a conical shape and expose the lead at the lower end of the pencil which exposed end will project through the opening of the conical portion of the body 10 and produce a sharp point.

' The sharpener is retained. on the pencil throughout. the life of the latter and whenever the point is used up or the lead breaks I a slight rotation of the sharpener will expose fresh leadforming a new sharp point. Instead of a series of sharp points 13 forming cutting elements, the conical part of the sharpener coil may be made of twisted wire 14 (Fig. 4) substantially of angular cross section, so that there will be a series of sharp edges 14 serving as cutting elements.

In the modification according to Fig. 5the coiled cutter is made of cylindrical wire 15 '95 whose surface is formed with helical: grooves 15 forming sharp edges 15 serving as cutting elements similar to ordinary drills.

It is obvious that various changes may be made in the construction of my sharpener without departing from the principle of my invention. I, therefore, do not wish to restrict myself to the details described and shown.

What I claim is:

1. A pencil sharpener comprising a wound wire body adapted to be mounted around and retained on a pencil during the life of the latter, means thereon to cause it to be automatically displaced longitudinally on said pencil when turned on its axis and cutting means on said body adapted to sharpen said pencil when said body is turned on its axis.

2. A pencil sharpener comprising a tubular wire body adapted to be movably mounted around a pencil and be retained thereon during the life of the pencil, means at one end of said body for causing the latter to be fed longitudinally on said pencil when rotated on its axis and cutting means at the opposite end of said body adapted to sharpen the pencil when said body is rotated.

3. A pencil sharpener comprising a tubular wire body adapted to be movably mounted around a pencil and be retained thereon during the life of the pencil, means at one end of said body for causing the latter to be fed longitudinally on said pencil when rotated on its axis, cutting means at the opposite end of said body adapted to sharpen the pencil when said body is turned and means for shielding the exposed part of the lead.

4:. A pencil sharpener comprising a tubular wire body adapted to be mounted around a pencil, a part of said body being cylindrical and another conical, the cylindrical portion being adapted to thread on the pencil and cause said body to feed longitudinally when turned on its axis and the conical part having cutting elements to sharpen the pencil when said body is turned.

5. A pencil sharpener comprising a tubular wire body having a cylindrical upper portion and a conical lower portion, the upper portion being threaded to grip the pencil and cause said body to feed longitudinally on said pencil when turned on its axis, and the lower portion having cutting elements to sharpen the pencil when said body is turned and means for shielding the exposed writing end of the pencil.

6. A pencil sharpener comprising a wound wire body, a portion of the convolutions of said windings forming a cylindrical tube and another portion forming a conical tube, said last named convolutions being spaced apart from each other and provided interiorly with sharpening means, and means on said cylindrical tube for automatically feeding said pencil into said conical tube when said body is rotated.

In testimony whereof I alfix my signature.

PAUL SIPTROTT. 

